Normalized difference vegetation index for desiccation evaluation with glyphosate + 2, 4-D in magnetized spray solution / Índice de vegetação por diferença normalizada para avaliação de dessecação com glyphosate + 2, 4-D em calda magnetizada

Water magnetization and geoprocessing are increasingly utilized tools in weed management. Our objective was to study the influence of water magnetization on herbicide efficiency and to verify whether there is a relationship between control scores and the normalized difference vegetation index (NDVI). In the laboratory experiment, water was subjected to magnetization and evaluated with respect to four characteristics. In the field experiment, plots of Brachiaria grass were subjected to treatments in a factorial scheme (6 × 2 + 1). Six herbicidal factors (doses of glyphosate and glyphosate + 2,4-D) and the magnetization or absence of magnetization of the spray solution were evaluated and compared against the control treatment (without spraying). Weed control assessments were carried out six times. Images were obtained using an embedded multispectral camera to determine the NDVI values. Data related to water characteristics were analyzed using the t test. Weed control and NDVI data were subjected to analysis of variance and are presented in regression graphs. Dispersion analysis of NDVI data was performed according to the control scores. The magnetization process decreased the pH of the water and increased the surface tension, but it did not influence the control scores or the NDVI. As the glyphosate dose was increased, the control scores were higher and the NDVI values were lower. Magnetized water did not affect the biological efficiency of the herbicides, and there was a strong correlation between the control scores and the NDVI values.

A magnetização da água e o geoprocessamento são ferramentas cada vez mais utilizadas no manejo de ervas daninhas. Nosso objetivo foi estudar a influência da magnetização da água na eficiência do herbicida e verificar se existe uma relação entre os escores de controle e o índice de vegetação por diferença normalizada (NDVI). No experimento de laboratório, a água foi submetida à magnetização e avaliada em relação a quatro características. No experimento de campo, parcelas de capim-braquiária foram submetidas a tratamentos em esquema fatorial (6 × 2 + 1). Seis fatores herbicidas (doses de glyphosate e glyphosate + 2,4-D) e a magnetização ou ausência de magnetização da calda foram avaliados e comparados com o tratamento controle (sem pulverização). Avaliações de controle de plantas daninhas foram realizadas seis vezes. As imagens foram obtidas usando uma câmera multiespectral incorporada para determinar os valores de NDVI. Os dados relacionados às características da água foram analisados por meio do teste t. O controle de plantas daninhas e os dados de NDVI foram submetidos à análise de variância e são apresentados em gráficos de regressão. A análise de dispersão dos dados NDVI foi realizada de acordo com os escores de controle. O processo de magnetização diminuiu o pH da água e aumentou a tensão superficial, mas não influenciou nos escores de controle ou no NDVI. Conforme a dose de glyphosate foi aumentada, os escores de controle foram maiores e os valores de NDVI foram menores. A água magnetizada não afetou a eficiência biológica dos herbicidas, e houve uma forte correlação entre os escores de controle e os valores de NDVI.

Normalized difference vegetation index for desiccation evaluation with glyphosate + 2,4-D in magnetized spray solution

Abstract Water magnetization and geoprocessing are increasingly utilized tools in weed management. Our objective was to study the influence of water magnetization on herbicide efficiency and to verify whether there is a relationship between control scores and the normalized difference vegetation index (NDVI). In the laboratory experiment, water was subjected to magnetization and evaluated with respect to four characteristics. In the field experiment, plots of Brachiaria grass were subjected to treatments in a factorial scheme (6 × 2 + 1). Six herbicidal factors (doses of glyphosate and glyphosate + 2,4-D) and the magnetization or absence of magnetization of the spray solution were evaluated and compared against the control treatment (without spraying). Weed control assessments were carried out six times. Images were obtained using an embedded multispectral camera to determine the NDVI values. Data related to water characteristics were analyzed using the t test. Weed control and NDVI data were subjected to analysis of variance and are presented in regression graphs. Dispersion analysis of NDVI data was performed according to the control scores. The magnetization process decreased the pH of the water and increased the surface tension, but it did not influence the control scores or the NDVI. As the glyphosate dose was increased, the control scores were higher and the NDVI values were lower. Magnetized water did not affect the biological efficiency of the herbicides, and there was a strong correlation between the control scores and the NDVI values.

Resumo A magnetização da água e o geoprocessamento são ferramentas cada vez mais utilizadas no manejo de ervas daninhas. Nosso objetivo foi estudar a influência da magnetização da água na eficiência do herbicida e verificar se existe uma relação entre os escores de controle e o índice de vegetação por diferença normalizada (NDVI). No experimento de laboratório, a água foi submetida à magnetização e avaliada em relação a quatro características. No experimento de campo, parcelas de capim-braquiária foram submetidas a tratamentos em esquema fatorial (6 × 2 + 1). Seis fatores herbicidas (doses de glyphosate e glyphosate + 2,4-D) e a magnetização ou ausência de magnetização da calda foram avaliados e comparados com o tratamento controle (sem pulverização). Avaliações de controle de plantas daninhas foram realizadas seis vezes. As imagens foram obtidas usando uma câmera multiespectral incorporada para determinar os valores de NDVI. Os dados relacionados às características da água foram analisados por meio do teste t. O controle de plantas daninhas e os dados de NDVI foram submetidos à análise de variância e são apresentados em gráficos de regressão. A análise de dispersão dos dados NDVI foi realizada de acordo com os escores de controle. O processo de magnetização diminuiu o pH da água e aumentou a tensão superficial, mas não influenciou nos escores de controle ou no NDVI. Conforme a dose de glyphosate foi aumentada, os escores de controle foram maiores e os valores de NDVI foram menores. A água magnetizada não afetou a eficiência biológica dos herbicidas, e houve uma forte correlação entre os escores de controle e os valores de NDVI.

Normalized difference vegetation index for desiccation evaluation with glyphosate + 2, 4-D in magnetized spray solution / Índice de vegetação por diferença normalizada para avaliação de dessecação com glyphosate + 2, 4-D em calda magnetizada

Abstract Water magnetization and geoprocessing are increasingly utilized tools in weed management. Our objective was to study the influence of water magnetization on herbicide efficiency and to verify whether there is a relationship between control scores and the normalized difference vegetation index (NDVI). In the laboratory experiment, water was subjected to magnetization and evaluated with respect to four characteristics. In the field experiment, plots of Brachiaria grass were subjected to treatments in a factorial scheme (6 × 2 + 1). Six herbicidal factors (doses of glyphosate and glyphosate + 2,4-D) and the magnetization or absence of magnetization of the spray solution were evaluated and compared against the control treatment (without spraying). Weed control assessments were carried out six times. Images were obtained using an embedded multispectral camera to determine the NDVI values. Data related to water characteristics were analyzed using the t test. Weed control and NDVI data were subjected to analysis of variance and are presented in regression graphs. Dispersion analysis of NDVI data was performed according to the control scores. The magnetization process decreased the pH of the water and increased the surface tension, but it did not influence the control scores or the NDVI. As the glyphosate dose was increased, the control scores were higher and the NDVI values were lower. Magnetized water did not affect the biological efficiency of the herbicides, and there was a strong correlation between the control scores and the NDVI values.

Resumo A magnetização da água e o geoprocessamento são ferramentas cada vez mais utilizadas no manejo de ervas daninhas. Nosso objetivo foi estudar a influência da magnetização da água na eficiência do herbicida e verificar se existe uma relação entre os escores de controle e o índice de vegetação por diferença normalizada (NDVI). No experimento de laboratório, a água foi submetida à magnetização e avaliada em relação a quatro características. No experimento de campo, parcelas de capim-braquiária foram submetidas a tratamentos em esquema fatorial (6 × 2 + 1). Seis fatores herbicidas (doses de glyphosate e glyphosate + 2,4-D) e a magnetização ou ausência de magnetização da calda foram avaliados e comparados com o tratamento controle (sem pulverização). Avaliações de controle de plantas daninhas foram realizadas seis vezes. As imagens foram obtidas usando uma câmera multiespectral incorporada para determinar os valores de NDVI. Os dados relacionados às características da água foram analisados ​​por meio do teste t. O controle de plantas daninhas e os dados de NDVI foram submetidos à análise de variância e são apresentados em gráficos de regressão. A análise de dispersão dos dados NDVI foi realizada de acordo com os escores de controle. O processo de magnetização diminuiu o pH da água e aumentou a tensão superficial, mas não influenciou nos escores de controle ou no NDVI. Conforme a dose de glyphosate foi aumentada, os escores de controle foram maiores e os valores de NDVI foram menores. A água magnetizada não afetou a eficiência biológica dos herbicidas, e houve uma forte correlação entre os escores de controle e os valores de NDVI.

Liquid nitrogen fertilization on the yield and phenologic variables of narrow-row cotton / Adubação nitrogenada líquida na produtividade e variáveis fenológicas em algodoeiro adensado

Slow-release liquid nitrogen fertilizer sources have been around since 1970. However, this technique is not widely used in the field, probably due to the low cost per ton of nitrogen in the solid form. This study aimed to evaluate the combination of the conventional and slow-release nitrogen fertilization on the yield and phenological variables in a narrow-row cotton crop. Treatments consisted of the combination of the nitrogen fertilizer applied as topdressing in solid form (via soil) and pulverized in the liquid form (via urea formaldehyde - UF): 0% of solid N + 0% of liquid N (0S0L); 100% of solid N + 0% of liquid N (100S0L); 75% of solid N + 25% of liquid N (75S25L); 50% of solid N + 50% of liquid N (50S50L); 25% of solid N + 75% of liquid N (25S75L); e 0% of solid N + 100% of liquid N (0S100L). The cotton crop was phenotypically evaluated at 35, 70, and 130 DAE (Days after emergence) and at the harvest time. The variation between the source of the solid nitrogen fertilizer applied to the soil (ammonium nitrate) and the liquid Nitrogen fertilizer applied by spraying (UF) affects the phenology, physiology, and yield components of the narrow-row cotton crop. The highest yield of the narrow-row cotton crop under the experimental conditions was achieved when 25% of the dose of the solid nitrogen fertilizer was applied as topdressing via soil, and 75% of the dose of the slow-release nitrogen fertilizer was sprayed. This technique provides higher profitability of the produced cotton in relation to the conventional application of the N solid fertilizer via soil.

Fontes de fertilizantes nitrogenados líquidos de liberação lenta existem desde 1970. No entanto, esta técnica não é amplamente utilizada no campo, provavelmente devido ao baixo custo por tonelada de nitrogênio na forma sólida. Este trabalho teve como objetivo avaliar a combinação da adubação nitrogenada convencional e de liberação lenta sobre a produtividade e as variáveis fenológicas em uma cultura de algodão de fileira estreita. Os tratamentos consistiram da combinação do fertilizante nitrogenado aplicado como cobertura na forma sólida (via solo) e pulverizado na forma líquida (via uréia formaldeído - UF): 0% de N sólido + 0% de N líquido (0S0L); 100% de N sólido + 0% de N líquido (100 S); 75% de N sólido + 25% de N líquido (75S25L); 50% de N sólido + 50% de N líquido (50S50L); 25% de N sólido + 75% de N líquido (25S75L); e 0% de N sólido + 100% de N líquido (0S100L). A cultura do algodão foi avaliada fenotipicamente aos 35, 70 e 130 DAE (dias após a emergência) e no momento da colheita. A variação entre a fonte de adubação nitrogenada aplicada ao solo (nitrato de amônio) e o fertilizante nitrogenado líquido aplicado por pulverização (UF) afeta os componentes fenológicos, fisiológicos e produtivos da cultura de algodão de fileiras estreitas. O maior rendimento da cultura de algodão de linha estreita nas condições experimentais foi alcançado quando 25% da dose do fertilizante de nitrogênio sólido foi aplicado como cobertura de solo via solo, e 75% da dose do fertilizante de nitrogênio de liberação lenta foi pulverizada. Esta técnica proporciona maior rentabilidade do algodão produzido em relação à aplicação convencional do fertilizante N via solo.

Relationship between vegetation indices and agronomic performance of maize varieties under different nitrogen rates / Relação entre índices de vegetação e desempenho agronômico de variedades de milho sob diferentes doses de nitrogênio

Precision agriculture is a set of techniques that assist the monitoring of the agronomic performance of the maize crop by using vegetation indices. This study aimed to verify the relationship between vegetation indices, plant height, leaf N content, and grain yield of three maize varieties, grown under high and low N as topdressing. The experiment was carried out at the Fundação de Apoio à Pesquisa Agropecuária de Chapadão (Fundação Chapadão), located in the municipality of Chapadão do Sul, during the 2017/2018 season. The experiment consisted of a randomized block design with four replications, arranged in a 3x2 split-plot scheme. The first factor (plots) corresponded to three open-pollinated maize varieties (BRS 4103, BRS Gorotuba, and SCS 154), and the second factor (subplots) consisted of two N rates applied as topdressing (80 and 160 kg- 1). All the evaluated variables showed varieties x N interaction. Vegetation indices in maize varieties were influenced by the N rate applied as topdressing. Normalized Difference Vegetation Index (NDVI) and Soil-adjusted Vegetation Index (SAVI) showed a higher correlation with plant height. At the same time, Normalized Difference Red Edge (NDRE) had a stronger association with leaf N content.

A agricultura de precisão é um conjunto de técnicas que auxiliam no monitoramento do desempenho agronômico da cultura do milho utilizando índices de vegetação. Este trabalho teve como objetivo verificar a relação entre índices de vegetação, altura de planta, teor de N foliar e rendimento de grãos de três variedades de milho, cultivadas sob alto e baixo N, em cobertura. O experimento foi realizado na Fundação de Apoio à Pesquisa Agropecuária de Chapadão, localizada no município de Chapadão do Sul, na safra 2017/2018. O experimento consistiu de um delineamento de blocos casualizados com quatro repetições, dispostos em esquema de parcelas subdivididas 3x2. O primeiro fator (parcelas) correspondeu a três variedades de milho de polinização aberta (BRS 4103, BRS Gorotuba e SCS 154), e o segundo fator (subparcelas) consistiu de duas doses de N aplicadas como cobertura (80 e 160 kg-1). Todas as variáveis avaliadas apresentaram interação variedades x N. Os índices de vegetação nas variedades de milho foram influenciados pela dose de N aplicada como cobertura. Os índices NDVI e SAVI mostraram uma maior correlação com a altura da planta, enquanto o NDRE apresentou uma associação mais forte com o conteúdo de N foliar.

Variación espacio-temporal de la respuesta espectral en manglares de La Habana, Cuba, evaluada con sensores remotos

Introducción: Los manglares son una de las formaciones vegetales de mayor relevancia global por los servicios ecosistémicos y roles ecológicos que desempeñan, y representan el 5 % de la superficie emergida de Cuba. No existen estudios previos que describan las variaciones en los índices espectrales de vegetación por sensores remotos en los manglares cubanos, pero con este tipo de variable se pueden constituir indicadores del estado de estos ecosistemas y emplearse en evaluaciones a nivel nacional. Objetivo: En el presente trabajo se evalúa la variabilidad espacial y temporal de dos índices espectrales de vegetación en cuatro manglares periurbanos de la ciudad de La Habana y se comparan con un sitio natural como control. Métodos: El estudio se desarrolló en las localidades de Bajo de Santa Ana, Cojímar, Rincón de Guanabo y la laguna El Cobre - Itabo y el control fue tomado en la ciénaga de Zapata. A través de la plataforma Climate Engine se extrajeron, de 2 460 imágenes satelitales LandSat, los valores promedio de los índices espectrales NDVI y EVI en 5 parcelas por cada localidad de estudio, entre 1984 y 2019. Las variables se compararon estadísticamente entre localidades y se describió su tendencia a lo largo del periodo de estudio. Resultados: Se detectaron diferencias geográficas en los índices, que pueden correlacionarse con las propiedades estructurales y grado de conservación de cada localidad. La tendencia global de los índices fue a un aumento, pero difirió entre localidades. Los menores cambios se produjeron en el sitio control y, entre los humedales periurbanos, en el Rincón de Guanabo y en Cojímar. El ordenamiento de las localidades a partir de variables espectrales fue consistente con el de grado de conservación general. Conclusiones: La respuesta espectral permitió caracterizar cada manglar de manera individualizada, mostrando relación aparente con las características ecológicas y de conservación de cada lugar. Es necesario continuar promoviendo estudios con sensores remotos de estas formaciones boscosas y generar indicadores sólidos que sustenten su uso en futuras investigaciones y monitoreos en manglares del Caribe.

Introduction: Mangroves are one of the most important forest types because of their ecosystem services and ecological roles. They represent 5 % of the emerged land of Cuba. No previous studies are describing spectral vegetation indexes variations by remote sensing in Cuban mangroves, but these variables can be used as indicators of the conservation status of the ecosystem and sustain national wide assessments. Objective: In the current paper we describe spatial and temporal variations in two spectral vegetation indexes in four near-city mangroves at Havana, Cuba and compare them to a natural control site. Methods: Study was conducted in localities named: Bajo de Santa Ana, Cojímar, Rincón de Guanabo, and El Cobre - Itabo lagoon and as control site was selected northern Zapata swamp. By using Climate Engineplatform we extract, from 2 460 Landsat satellite images, mean values of spectral indexes NDVI and EVI in 5 parcels per locality, from 1984 to 2019. Variables were statistically compared among localities and the global trend was described. Results: We detect geographic differences in both indexes, which can be related to structural properties and conservation degree of mangroves in each locality. Global trend of indexes was to increase, but differently among localities. Slighter changes appear in the control site and, among near city mangroves, in Rincón de Guanabo and Cojímar. The ordering of localities from spectral variables was consistent with the ranking in general conservation degree. Conclusions: Spectral responses describe uniquely each mangrove forest, in concordance to each ecological and conservation characteristics. There is a need for promoting studies using remote sensors at these forest types and to generate strong and reliable indicators that can sustain future researches and monitoring schemes in Caribbean mangroves.

Analysis of the landscape complexity and heterogeneity of the Pantanal wetland / Análise da complexidade e heterogeneidade da paisagem do Pantanal

Abstract This is the first report on analysis of habitat complexity and heterogeneity of the Pantanal wetland. The Pantanal encompasses a peculiar mosaic of environments, being important to evaluate and monitor this area concerning conservation of biodiversity. Our objective was to indirectly measure the habitat complexity and heterogeneity of the mosaic forming the sub-regions of the Pantanal, by means of remote sensing. We obtained free images of Normalized Difference Vegetation Index (NDVI) from the sensor MODIS and calculated the mean value (complexity) and standard deviation (heterogeneity) for each sub-region in the years 2000, 2008 and 2015. The sub-regions of Poconé, Canoeira, Paraguai and Aquidauana presented the highest values of complexity (mean NDVI), between 0.69 and 0.64 in the evaluated years. The highest horizontal heterogeneity (NDVI standard deviation) was observed in the sub-region of Tuiuiú, with values of 0.19 in the years 2000 and 2015, and 0.21 in the year 2008. We concluded that the use of NDVI to estimate landscape parameters is an efficient tool for assessment and monitoring of the complexity and heterogeneity of the Pantanal habitats, applicable in other regions.

Resumo Este é o primeiro trabalho sobre análise da complexidade e heterogeneidade de habitats do Pantanal. O Pantanal é constituído por um mosaico de ambientes com características peculiares, sendo importante a avaliação e o monitoramento dessa área voltado para a conservação da biodiversidade. O objetivo do estudo é mensurar de forma indireta a complexidade e a heterogeneidade do mosaico de habitats os quais formam as sub-regiões do Pantanal, por meio do sensoriamento remoto. Foram obtidas, gratuitamente, imagens de índice de vegetação por diferença normalizada (NDVI) do sensor MODIS e calculado o valor de média (complexidade) e desvio padrão (heterogeneidade) para cada sub-região do Pantanal, para os anos de 2000, 2008 e 2015. Os pantanais de Poconé, Canoeira, Paraguai e Aquidauana são as regiões que apresentaram os maiores valores de complexidade (NDVI médio), variando entre 0.69 a 0.64 para os anos avaliados. Maior heterogeneidade (NDVI desvio padrão) foi observada na sub-região pantaneira do Tuiuiú, sendo o valor para os anos de 2000 e 2015 igual a 0.19 e para o ano de 2008 o valor de 0.21, o que implica que a região tem a maior heterogeneidade horizontal quando comparada com as demais sub-regiões. Constata-se que o uso de NDVI na estimativa de parâmetros da paisagem é uma ferramenta eficiente para o reconhecimento e monitoramento da complexidade e heterogeneidade de habitats do Pantanal, replicável em outras regiões.

Changes in vegetation cover of the Pantanal wetland detected by Vegetation Index: a strategy for conservation / Mudanças na cobertura da vegetação do Pantanal dectadas por Índice de Vegetação: uma estratégia de conservação

The Brazilian Pantanal wetland undergoes landscape alterations that can cause impacts on hydrological processes, changing the flood pulse. The objective of this work is to analyse the vegetation cover of the Pantanal in the period of 2000, 2008 and 2015, and to make a projection for 2030. Therefore, NDVI from the sensor MODIS was analysed and the transition matrix was calculated by the DINAMICA EGO. The methods adopted were open sources. The results were worrisome, indicating alterations of the vegetation cover of the Pantanal, with an increase of short vegetation (grasslands or pastures) in the evaluated period. The projection pointed out that in 2030 the Brazilian Pantanal wetland area will be covered by 78% of short vegetation and only 14% of dense (arboreal-shrubby) vegetation. The approach can be a useful tool for conservation of the Brazilian Pantanal wetland.

O Pantanal brasileiro sofre alterações em sua paisagem que podem provocar impactos sobre os processos hidrológicos, afetando os pulsos de inundação. O objetivo do trabalho é analisar a cobertura vegetal do Pantanal no período de 2000, 2008 e 2015 e realizar a projeção quantitativa para 2030. Portanto, foram analisados dados NDVI do sensor MODIS e a análise da matriz de transição foi calculada pelo DINAMICA EGO. Os métodos utilizados foram todos em softwares livres. Os resultados foram preocupantes, indicando alteração da cobertura vegetal do Pantanal, com o aumento da vegetação rasteira (campos ou pastagens) no período avaliado. A projeção apontou que em 2030 a área do Pantanal será coberta por 78% de vegetação rasteira e apenas 14% de vegetação densa (arbóreo-arbustiva). A abordagem apresentada pode ser uma ferramenta útil para a conservação do Pantanal.

Analysis of the landscape complexity and heterogeneity of the Pantanal wetland

Abstract This is the first report on analysis of habitat complexity and heterogeneity of the Pantanal wetland. The Pantanal encompasses a peculiar mosaic of environments, being important to evaluate and monitor this area concerning conservation of biodiversity. Our objective was to indirectly measure the habitat complexity and heterogeneity of the mosaic forming the sub-regions of the Pantanal, by means of remote sensing. We obtained free images of Normalized Difference Vegetation Index (NDVI) from the sensor MODIS and calculated the mean value (complexity) and standard deviation (heterogeneity) for each sub-region in the years 2000, 2008 and 2015. The sub-regions of Poconé, Canoeira, Paraguai and Aquidauana presented the highest values of complexity (mean NDVI), between 0.69 and 0.64 in the evaluated years. The highest horizontal heterogeneity (NDVI standard deviation) was observed in the sub-region of Tuiuiú, with values of 0.19 in the years 2000 and 2015, and 0.21 in the year 2008. We concluded that the use of NDVI to estimate landscape parameters is an efficient tool for assessment and monitoring of the complexity and heterogeneity of the Pantanal habitats, applicable in other regions.

Resumo Este é o primeiro trabalho sobre análise da complexidade e heterogeneidade de habitats do Pantanal. O Pantanal é constituído por um mosaico de ambientes com características peculiares, sendo importante a avaliação e o monitoramento dessa área voltado para a conservação da biodiversidade. O objetivo do estudo é mensurar de forma indireta a complexidade e a heterogeneidade do mosaico de habitats os quais formam as sub-regiões do Pantanal, por meio do sensoriamento remoto. Foram obtidas, gratuitamente, imagens de índice de vegetação por diferença normalizada (NDVI) do sensor MODIS e calculado o valor de média (complexidade) e desvio padrão (heterogeneidade) para cada sub-região do Pantanal, para os anos de 2000, 2008 e 2015. Os pantanais de Poconé, Canoeira, Paraguai e Aquidauana são as regiões que apresentaram os maiores valores de complexidade (NDVI médio), variando entre 0.69 a 0.64 para os anos avaliados. Maior heterogeneidade (NDVI desvio padrão) foi observada na sub-região pantaneira do Tuiuiú, sendo o valor para os anos de 2000 e 2015 igual a 0.19 e para o ano de 2008 o valor de 0.21, o que implica que a região tem a maior heterogeneidade horizontal quando comparada com as demais sub-regiões. Constata-se que o uso de NDVI na estimativa de parâmetros da paisagem é uma ferramenta eficiente para o reconhecimento e monitoramento da complexidade e heterogeneidade de habitats do Pantanal, replicável em outras regiões.

Study on Remote Sensing Monitoring Method of Aquatic Medicine Materials Euryale ferox Salisb Based on Multi-source Satellite Remote Sensing Image / 世界科学技术-中医药现代化

Multi-source satellite remote sensing technology can be used to monitor the distribution and growth status of aquatic plant species on a large scale.In this paper,C,aoyou Lake was selected as the research area.Aquatic medicine material Euryaleferox Salisb was used as the research object.The spectral characteristics of plants in Euryaleferox Salisb growing area were analyzed by ASD portable spectrometer and the remote sensing image of Pléiades and GF-1.The spectral range of species was obtained.And the decision tree algorithm model was constructed,which were used to extract the information of Euryale ferox Salisb from remote sensing images.Through verification,the results showed that the accuracy of comprehensive classification was 83％.It was concluded that multi-source satellite remote sensing image and GIS spatial analysis technology can accurately reflect the area and distribution of aquatic medicine material Euryale ferox Salisb.

Imagens multiespectrais para avaliação de índice de área foliar e massa seca do capim 'Tifton 85', sob adubação nitrogenada / Multispectral imaging for leaf area index and dry mass evaluation of 'Tifton 85' bermudagrass under nitrogen fertilization

O presente trabalho teve por objetivo analisar as respostas do capim 'Tifton 85' (Cynodon spp.) à adubação nitrogenada, em termos de área foliar verde e de massa seca da parte aérea, utilizando índices calculados a partir de informações contidas em imagens multiespectrais, em comparação com indicadores obtidos por métodos diretos. Os tratamentos consistiram de quatro doses de N-ureia (0; 100; 150 e 200 kg ha-1), dispostos em um desenho experimental inteiramente casualizado, com quatro repetições. Aos 26 dias, após um corte de uniformização, foram determinados os seguintes atributos do dossel: o Índice de Área Foliar (IAF), a massa seca da parte aérea (MSPA), o índice de cobertura verde (ICV), utilizando uma câmara digital na faixa do visível e o Índice de Vegetação por Diferença Normalizada (NDVI), utilizando uma câmara multiespectral. Os quatro atributos do dossel vegetativo responderam positivamente à adubação nitrogenada. Enquanto o ICV mostrou relações curvilineares com o IAF e a MSPA (R² IAF=0,89; R² MSPA=0,87), o NDVI mostrou relações lineares (r² IAF=0,62; r2 MSPA=0,64), sem evidenciar tendência à saturação. Foi concluído que é possível avaliar a adubação nitrogenada em pastagens de Cynodon spp., utilizando análise de imagens, e que tanto o NDVI quanto o ICV podem ser utilizados como indicadores de produtividade do capim Tifton 85.

The purpose of this study was to verify the responses of 'Tifton 85' bermudagrass (Cynodon spp.) to nitrogen fertilization in terms of green leaf area and aerial dry mass, using indices calculated from spectral information contained in multispectral images, in comparison with indicators obtained by direct methods. The bermudagrass was managed under four N treatments (0; 100; 150 and 200 kg ha-1) using a completely randomized experimental design, with four repetitions. Twenty six days after a standardization cut, four canopy traits were determined: leaf area index (LAI), aerial dry mass (ADM), green coverage index (GCI), using a RGB camera and the Normalized Difference Vegetation Index (NDVI), using a multispectral camera. All the traits responded positively to nitrogen fertilization. However, while the GCI showed curvilinear relationships with LAI (R²=0.89) and ADM (R²=0.87), the NDVI showed linear relationships with both (r² LAI=0.62; r² ADM=0.64) without evidences of saturated responses. It was concluded that it is possible to evaluate nitrogen fertilizer on pastures of Cynodon spp., using image analysis. NDVI and ICV can be used as productivity indicators of 'Tifton 85' bermudagrass.

Application of Remotely-sensed Data for Modeling Malaria Infection in Lokoja, Nigeria.

Aims: To estimate incidences of malaria infection in an urban setting using Remotely sensed data and matching same with hospital records to validate the use of Remote sensing data as a methodology for studying the prevalence of malaria. Study Design: Analyses of 2006 Nigeriasat-1 and Land sat ETM+satellite data for modeling malaria infection. Place and Duration of Study: Lokoja, Capital city of Kogi State in Central Nigeria, between March 2012 and January 2013. Methodology: Extraction of land use types, NDVI and LST maps using ILWIS 3.3 and Idrisi software. Cross tabulation of extracted maps to carry out correlational analyses while buffer analysis was conducted to ascertain risk zones of malaria infection in the town. The clinical data was used in determining the recorded incidence of malaria in the study area. Results: Built-up area, sand bars and vacant land occupy least land cover (i.e. 28.31%) while urban agricultural land, vegetation and water bodies covered 344.33km2 (59.72%), 41.98km2 (7.28%) and 18.51km2 (3.21%), respectively. The LSE value ranges from 0.92 to 0.989 with an average of 0.955 whereas the highest emissivity is recorded where vegetation is very dense and the lowest recorded for Sand bars. The LST for sand bars, vacant land and built-up area recorded the highest average temperatures of 41.13°C, 35.66°C and 34.56°C, respectively. The highest negative correlation was found in vegetation (-0.96) with other negative values recorded for urban agricultural land and water bodies. The lowest correlation (0.65) was recorded from areas covered with sand bars. The UHI map shows that temperatures at the periphery are lower (about 18°C) but higher at the core (from 26°C to 40°C). Conclusion: The interplay of NDVI, LST and land use/cover types of Lokoja provides the impetus for the rising incidence of malaria in Lokoja town. Proper urban planning which will support sufficient drainages, effective waste removal, sanitary landfill sites, vegetation control, fumigation, etc. can boost sanitary conditions whilst minimizing the availability of breeding sites for mosquito larvae. At the household levels, extensive use of bed nets and periodic fumigation appear to be the most appropriate short-term measures for curtailing the incidences of malaria at the study area.

Semiarid Mixed Grassland under Climate Change Using AVHRR NDVI Data.

The topography effects on vegetation biomass under climate change impact have been ignored in prairie regions as it is not as significant as in mountain areas. This paper aims to investigate the topographic effects on vegetation biomass under climate change in semiarid Canadian mixed grass prairie. The study site is Grasslands National Park (GNP) and the study period is from 1985 to 2007. Data used include dry green biomass data sampled from June to July of 2003 to 2005, 10-day Advanced Very High Resolution Radiometer (AVHRR) 1km Normalized Difference Vegetation Index (NDVI) composites of 1985 to 2007, and Global Digital Elevation Model derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER GDEM) data with 90 m resolution. To achieve the objective, the applicability of AVHRR NDVI data being a proxy of vegetation biomass was investigated. Then, the range and standard deviation (SD) of each individual vegetation patch in both valley and upland grasslands were calculated. In addition, the variation trend of valley and upland vegetation was analyzed respectively using the Mann-Kendall (M-K) test and the Sen’s slope. The results indicate that the interannual variation of vegetation biomass at GNP can be fairly well represented by AVHRR 1 km NDVI data. Although some patches in valley grassland have similar NDVI range and SD values as those in upland grassland, the others have much smaller range and SD values than the highest range (0.154) and SD (0.045) of upland grassland. The M-K test and Sen’s slope analyses indicate that NDVI had an increase trend with a larger slope (0.0005) in upland and a smaller slope (0.0002) in valley grassland. It is concluded that climatic variation has more effects on upland grassland than valley grassland in GNP. Topography effects in prairie regions should not be ignored.

Estimativa do potencial produtivo em trigo utilizando sensor óptico ativo para adubação nitrogenada em taxa variável / Wheat yield potential estimation using active optical sensor for site-specific nitrogen fertilization

A adubação nitrogenada em trigo é baseada no potencial produtivo da cultura, teor de matéria orgânica do solo e cultura antecessora. A definição do potencial produtivo é complexa, pois este varia com as condições meteorológicas de cada ano específico. O objetivo deste trabalho foi avaliar a relação entre o índice de vegetação por diferença normalizada (NDVI), medido por sensor óptico ativo e o rendimento de grãos em quatro cultivares de trigo, visando a desenvolver procedimentos para a adubação nitrogenada em cobertura em taxa variável. O experimento foi realizado em campo em 2009. Foram avaliados o NDVI em diferentes estádios de desenvolvimento e o rendimento de grãos. As leituras do NDVI ao longo do ciclo ativo foram eficientes em identificar variações de produtividade do trigo. Assim, o potencial de produtividade pode ser estimado através de medições desse índice durante a ontogenia da planta. Pode-se adotar um modelo único para descrever a relação entre NDVI e potencial produtivo para as cultivares testadas neste trabalho.

Nitrogen fertilization in spring wheat is based on yield potential, soil organic matter content and previous crop. Yield potential definition is difficult, since it is affected by weather conditions. The objective of this research was to evaluate the relationship between Normalized Difference Vegetation Index (NDVI) measured by an active sensor and grain yield of four wheat cultivars. The experiment was carried out at field conditions in 2009. NDVI in different growth stages and grain yield were evaluated. NDVI measured was efficient to detect growth variability generated by N availability and correlated well with grain yield for all cultivars tested, indicating that yield potential can be estimated by NDVI evaluations during crop ontogeny. One single model for the relationship between NDVI and yield potential can be used considering cultivars used in this research.

Delimitation of kala-azar risk areas in the district of Vaishali in Bihar (India) using a geo-environmental approach

Remote sensing and geographical information technologies were used to discriminate areas of high and low risk for contracting kala-azar or visceral leishmaniasis. Satellite data were digitally processed to generate maps of land cover and spectral indices, such as the normalised difference vegetation index and wetness index. To map estimated vector abundance and indoor climate data, local polynomial interpolations were used based on the weightage values. Attribute layers were prepared based on illiteracy and the unemployed proportion of the population and associated with village boundaries. Pearson's correlation coefficient was used to estimate the relationship between environmental variables and disease incidence across the study area. The cell values for each input raster in the analysis were assigned values from the evaluation scale. Simple weighting/ratings based on the degree of favourable conditions for kala-azar transmission were used for all the variables, leading to geo-environmental risk model. Variables such as, land use/land cover, vegetation conditions, surface dampness, the indoor climate, illiteracy rates and the size of the unemployed population were considered for inclusion in the geo-environmental kala-azar risk model. The risk model was stratified into areas of "risk"and "non-risk"for the disease, based on calculation of risk indices. The described approach constitutes a promising tool for microlevel kala-azar surveillance and aids in directing control efforts.

A comparative evaluation of end-emic and non-endemic region of visceral leishmaniasis (Kala-azar) in India with ground survey and space technology

In visceral leishmaniasis, phlebotomine vectors are targets for control measures. Understanding the ecosystem of the vectors is a prerequisite for creating these control measures. This study endeavours to delineate the suitable locations of Phlebotomus argentipes with relation to environmental characteristics between endemic and non-endemic districts in India. A cross-sectional survey was conducted on 25 villages in each district. Environmental data were obtained through remote sensing images and vector density was measured using a CDC light trap. Simple linear regression analysis was used to measure the association between climatic parameters and vector density. Using factor analysis, the relationship between land cover classes and P. argentipes density among the villages in both districts was investigated. The results of the regression analysis indicated that indoor temperature and relative humidity are the best predictors for P. argentipes distribution. Factor analysis confirmed breeding preferences for P. argentipes by landscape element. Minimum Normalised Difference Vegetation Index, marshy land and orchard/settlement produced high loading in an endemic region, whereas water bodies and dense forest were preferred in non-endemic sites. Soil properties between the two districts were studied and indicated that soil pH and moisture content is higher in endemic sites compared to non-endemic sites. The present study should be utilised to make critical decisions for vector surveillance and controlling Kala-azar disease vectors.

Caracterização espectral multitemporal dos cereais de estação fria em imagens de satélite com média resolução espacial / Multitemporal spectral characterization of cool season cereals in satellite images with moderate spatial resolution

A fim de avaliar os padrões de resposta de áreas cultivadas com cereais de estação fria destinados para pastagens e para produção de grãos em imagens de satélite, foram analisados perfis temporais de índice de vegetação por diferença normalizada (NDVI), adquiridos em 29 áreas cultivadas com trigo e azevém anual, nos Estados do Rio Grande do Sul e Paraná. Para cada área foi informada a espécie cultivada (trigo ou azevém anual) e a coordenada do ponto central da área adquirido por meio do Global Positioning System (GPS). Foram usadas as imagens do sensor MODIS (Moderate Resolution Imaging Spectroradiometer), com resolução espacial de 250 metros, sobre cada área monitorada, de onde os valores de NDVI foram extraídos. Os perfis temporais de NDVI mostraram que os cultivos de produção de grãos têm um comportamento espectral típico de cultivos agrícolas, enquanto que, nas áreas cultivadas para a produção de pastagem, não foi observado esse mesmo padrão. As diferenças nos padrões temporais observadas se devem a modificações que o pastoreio impõe na fenologia e na morfologia dessas plantas.

In order to evaluate the satellite image patterns between such cool season cereals cultivated areas intended for grazing or grain production, Normalized Difference Vegetation Index (NDVI) temporal profiles were analyzed. This data was acquired from twenty nine wheat and annual ryegrass cultivated areas in the states of Rio Grande do Sul and Paraná. For each area, the cultivated species (wheat or ryegrass), as well as the respective central point coordinates, acquired via Global Positioning System (GPS) was informed. NDVI values were extracted over each monitored area from MODIS (Moderate Resolution Imaging Spectroradiometer) sensor images, with spatial resolution of 250 meters. The NDVI temporal profiles showed that grain production areas have a typical agricultural field spectral pattern. The same pattern was not observed for the grazing pasture areas. The differences observed in these temporal patterns are defined by the changes that grazing has imposed on the phenology and morphology of these plants.

Mapeamento e quantificação de parâmetros biofísicos e radiação líquida em área de algodoeiro irrigado / Mapping and quantification of biophysical parameters and net radiation over irrigated cotton fields

O sensoriamento remoto tem se mostrado eficaz na avaliação de fluxos de energia e de propriedades biofísicas de superfícies vegetadas em escala regional. No presente trabalho, utilizou-se o algoritmo SEBAL - Surface Energy Balance Algorithm for Land e imagens TM - Landsat 5 para mapeamento e quantificação do albedo (α), NDVI, temperatura da superfície (Ts) e radiação líquida (Rn) em área de algodão irrigado por pivô central, na Fazenda Busato (13,25º S; 43,42º W; 436 m), município de Bom Jesus da Lapa, Bahia. Seis imagens de céu limpo ao longo do período da cultura (janeiro a agosto de 2007) e os respectivos dados meteorológicos foram utilizados para implementação do algoritmo. Após o processamento digital das imagens, verificou-se nítida relação dos parâmetros α, Ts e NDVI com o desenvolvimento da cultura. Os menores valores de α (10 a 20 por cento) e Ts (< 24ºC) e os maiores de NDVI (>0,75) ocorreram na fase de máxima cobertura do solo. A radiação líquida (Rn) diminuiu progressivamente com o tempo, influenciada, principalmente, pela diminuição da radiação solar incidente com o aumento do ângulo zenital. Os valores de Rn variaram de 430 W m-2 a 700 W m-2 nos pivos cultivados. A técnica de sensoriamento empregada capturou de forma nítida a variabilidade temporal e espacial de Rn e dos parâmetros biofísicos, cujos valores encontrados são compatíveis com os reportados na literatura para a mesma cultura sob regime de irrigação.

Remote sensing is currently an important tool for evaluation of net radiation and biophysical parameters over vegetated surfaces on a regional scale. In this research, the SEBAL - Surface Energy Balance Algorithm for Land and TM - Landsat 5 images were used to map and quantify the albedo (α), NDVI, surface temperature (Ts) and net radiation (Rn) of center-pivot irrigated cotton fields in the Busato Farm (13.25º S; 43.42º W; 436 m asl), western of State of Bahia, Brazil. Images from six clear-sky days during the cropping season (January to August 2007) and the corresponding meteorological data were used to run SEBAL. Results showed a clear relationship between α, NDVI, and Ts and crop development. The lowest values of α (10 to 20 percent) and Ts (< 24ºC), as well as the highest values of NDVI (> 0.75), occurred at the time of maximum ground cover. Net radiation decreased progressively with time, following the decrease of the incident solar radiation with increasing solar zenith angle. In the cropped center pivots, Rn ranged from 430 Wm-2 to 700 Wm-2. The remote sensing technique used in this study was consistent in capturing the temporal and spatial variability of the biophysical parameters and net radiation over the irrigated cotton, and their values are in agreement with those reported in the literature for the same crop in irrigated areas.

Mapping tropical dry forest habitats integrating Landsat NDVI, Ikonos imagery, and topographic information in the Caribbean Island of Mona

Assessing the status of tropical dry forest habitats using remote sensing technologies is one of the research priorities for Neotropical forests. We developed a simple method for mapping vegetation and habitats in a tropical dry forest reserve, Mona Island, Puerto Rico, by integrating the Normalized Difference vegetation Index (NDvI) from Landsat, topographic information, and high-resolution Ikonos imagery. The method was practical for identifying vegetation types in areas with a great variety of plant communities and complex relief, and can be adapted to other dry forest habitats of the Caribbean Islands. NDvI was useful for identifying the distribution of forests, woodlands, and shrubland, providing a natural representation of the vegetation patterns on the island. The use of Ikonos imagery allowed increasing the number of land cover classes. As a result, sixteen land-cover types were mapped over the 5 500 ha area, with a kappa coefficient of accuracy equal to 79 %. This map is a central piece for modeling vertebrate species distribution and biodiversity patterns by the Puerto Rico Gap Analysis Project, and it is of great value for assisting research and management actions in the island. Rev. Biol. Trop. 56 (2): 625-639. Epub 2008 June 30.

El estudio y evaluación de los bosques tropicales secos mediante herramientas de teledetección es una de las prioridades de investigación en los ambientes neotropicales. Desarrollamos una metodología simple para mapear la vegetación de la isla de Mona, Puerto Rico, mediante el uso del índice de vegetación normalizado (NDVI por sus siglas en inglés) de Landsat, información topográfica, e imágenes auxiliares de alta resolución Ikonos. La metodología fue útil para identificar las clases de vegetación en un área de gran variedad de comunidades vegetales y relieve complejo, y puede ser adaptada a otras regiones de bosque seco de las islas del Caribe. El NDVI permitió identificar la distribución de los bosques cerrados, abiertos, y arbustos, proveyendo una representación natural de los patrones de vegetación en la isla. Las imágenes de Ikonos permitieron incrementar el número de clases detectadas. Como resultado, mapeamos 16 clases de cobertura del terreno en las 5 500 hectáreas de la isla de Mona, con un coeficiente de concordancia kappa de un 79%. La información obtenida en este estudio será utilizada para modelar la distribución de los vertebrados terrestres y patrones de biodiversidad en la isla, como parte del proyecto Gap Análisis de Puerto Rico, y es de gran valor para asistir en las actividades de investigación y manejo en la isla.